The present invention is particularly applicable to communication systems employing electromagnetic radiation in the infrared range of the spectrum. An example would be an IrDA communication system. IrDA interfaces are being implemented, for instance, to establish a communications link between a computer and a printer. IrDA communication can also be used for computer to computer communications as well as for communication between a variety of other types of peripherals.
To date, the range of such communication systems has been hampered by 1) the need to ensure safety by limiting the system's energy output, 2) the desire to provide a system that does not require the transmitting unit to be aimed with pinpoint accuracy toward the receiving unit, and 3) the need to implement a low cost, low power solution. Safety issues arise, for example, because the human eye can be damaged by excessive exposure to the infrared signal. Presently, for example, it is not uncommon for devices communicating via IrDA protocol to be required to be within one or two meters of each other to establish reliable communications.
It would be highly desirable to develop an IrDA system capable of communicating efficiently over greater distances. For instance, a range of ten meters or more would be very useful in many applications. Accordingly, it is the aim of this invention to create a system for enabling IrDA communications over such distances. If implemented in a low cost and "eye safe" manner, such a result would greatly increase the variety of devices to which this technology would be applied.